عنوان مقاله [English]
Algebraic expressions are the important part of Algebra and it's deep understanding necessory for solving algebraic problems .The purpose of this study was to investigate students' understanding of the 7th, 8th and 9th grade of algebraic expressions. 400 students were selected by multistage cluster sampling from 7th, 8th and 9th grades students, in Tehran. A researcher-made test was designed and implemented. Out of 400 students, 15 students were selected and semi-structured interviews were conducted in order to clarify and interpret students' perceptions. The results of the test and interviews showed that most students have a poor structural understanding of algebraic expressions and they have understood them merely procedurally. Increasing academic bases did not almost improve structural understanding, but procedural understanding improves with increasing levels.
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